Re: I lied, another question / problem

Roman Neuhauser wrote: > # jochem@iamjochem.com / 2007-01-17 11:41:54 +0100: >> Roman Neuhauser wrote: >>> # jochem@iamjochem.com / 2007-01-17 01:42:09 +0100: >>>> if (!preg_match("#^[A-Z0-9]+\$#i", $s)) { >>>> (ps the above is a crappy regexp for real world use imho, but it serves >>>> the purpose of example) >>> >>> It's dangerous. >> why dangerous? >> >> given that this page: >> http://php.net/manual/en/function.ctype-alnum.php >> says, and I quote: >> >> "Checks if all of the characters in the provided string, text, are >> alphanumeric. In the standard C locale letters are just [A-Za-z] and >> the function is equivalent to preg_match('/^[a-z0-9]+$/iD', $text). >> " > > re_format(7) on FreeBSD: > > A bracket expression is a list of characters enclosed in `[]'. > (...) > If two characters in the list are separated by `-', this is > shorthand for the full range of characters between those two > (inclusive) in the collating sequence, e.g. `[0-9]' in ASCII > matches any decimal digit. > (...) > Ranges are very collating-sequence-dependent, and portable programs > should avoid relying on them. one other thing ... wouldn't it be fair to assume (safety through paranoia) that ctype_alnum() would suffer the same problem? (given the manual's indication that ctype_alnum() and the offending regexp are equivalent?) >